Catalytic ozonation with coal-based activated carbon(carbozone)followed by GAC(granular activated carbon)filtration was compared with ozone-GAC process for water purification.Songhua River water pretreated with traditional processes was used as influent in the continuous-flow experiments.The carbozone-GAC process performed better than the ozone-GAC process during the 9.5-months operation period.The organic removal rate in carbozone was found to be very high in the initial operation period,and then gradually decreased to a steady level.At the steady state of operation,the average removal rates of permanganate index(PI)and UV254 were 25.8% and 67.8% in carbozone,and 6.6% and 53.7% in ozonation alone,respectively.The carbozone process also achieved a higher DOC removal than ozonation alone,and moreover,the number of semi-volatile organic compounds detected with GC/MS decreased from 44 to 28 in carbozone and 34 in ozonation alone,respectively.The catalyst surface became more acidic during the long-term operation with its PHPZC(pH at which its surface is zero charged)decreased from 7.0 to 6.2.In addition,the physical characteristics of the catalyst were also changed during the operation.